"Most studies consider soil CO2 effluxes as directly corresponding to soil respiration. However, in the short term the soil CO2 efflux can deviate from instantaneous soil respiration whenever a change occurs in the amount of CO2 stored in the soil pore-spaces. Gaps in soil CO2 efflux measurements usually are filled using the soil temperature as a predictor. The relationship between soil temperature and soil CO2 efflux has been defined using exponential functions, most commonly the Arrhenius functions or Q10 models. However, growing evidence suggests that the soil CO2 efflux does not always follow the expected Arrhenius or Q10 temperature response; rather, soil CO2 effluxes show a hysteretic response. This hysteretic response has generated a growing call for deeper understanding of the different factors and processes limiting soil carbon metabolism and the soil CO2 efflux. The objective of this proposal is to use a combination of field and controlled environment experiments to identify and quantify the causes and consequences of temperature hysteresis and soil CO2 storage with regard to the soil CO2 efflux, which will lead to improved ecosystem models for regional-to-global carbon cycle quantification."